The invention relates to a device for automatically attaching cover slips to microscope slides carrying a specimen for microscopic examination and a mounting medium, comprising a lifting means having a holder in which there are mounted a pair of mutually spaced suction cups extending in a vertical plane, and an abutment body arranged between and outside of the suction cups and having a downwards convexly curved abutment surface for abutment against a cover slip retained by the suction cups.
On the market there exist several types of machines or apparatuses carrying out glueing of cover slips on microscope slides. An apparatus of this type is known, for example, from the international patent application No. PCT/NO93/00188 (WO 94/14097). In this apparatus, a fetching means for the cover slips comprises a pair of suction cups mounted at a suitable mutual distance in a holder for retaining the end portions of a cover slip, a downwards convexly curved resilient abutment surface being arranged between and outside of the suction cups, So that the suction cups, when activated, pull the underlying cover slip up to a slightly curved position in abutment against the resilient abutment surface.
Another example of such an apparatus is known from the international patent application No. PCT/AU95/00035 (WO 95/20176). A transfer head for cover slips comprises a vertically extending, spring-loaded plunger arranged between a pair of spaced suction cups, the axis of the suction cups being inclined outwardly and downwardly relative to the vertical axis of the plunger, and the plunger, in its downwardly extended position, being below the level of the suction cups, and control means are arranged to control the movement of the transfer head and the suction pressure to one or both of the suction cups.
In machines and apparatuses of the type in question it is important that the period from the time when the tissue specimens are taken out from the staining process until they are sealed, is as short as possible. A dehydration of the specimens results in poorer sealing and readability of the tissue condition, air bubbles then arising in the tissue. The air bubbles trapped during the process of placing a cover slip on a microscope slide with mounting medium thereon, something which frequently occurs with today""s systems, normally will not disappear by capillary action only.
The object of the invention is to provide a device which, in a particularly efficient manner, removes air bubbles occurring in the tissue specimens and the mounting medium in connection with attachment of cover glasses on microscope slides.
According to the invention there is provided a device of the introductorily stated type wherein the abutment body, at an end portion thereof situated laterally outside of the suction cups, is rotatably mounted in the holder about an axis extending transversely relative to said vertical plane, and wherein a means is provided causing the abutment body to be limitedly rotatable in the holder to each side of an essentially horizontal intermediate position.
By means of the device according to the invention one achieves a controlled force which moves gradually along the cover slip during the placing thereof on the microscope slide, the abutment body operating as a xe2x80x9crolling shoexe2x80x9d which, by its rotating movement, rolls along the cover slip from one end thereof to the other. In this manner there is achieved that all the trapped air bubbles are guided towards one end of the cover slip, and the air is pressed out from this end by means of the controlled mechanical force from the rolling shoe.